We inherit more than just wisdom and wealth from our parents. We inherit genes which shape not only our appearance and our personality traits but also our risk for certain diseases- including the dreaded C-cancer. While a majority of cancers happen because of "somatic" mutations and are related to non-inheritable factors like smoking, lifestyle or other insults to the body, the type of interest in this article is the "hereditary" ones. These represent about 10-15% of all cases.
We all know Cancer arises from the uncontrolled growth of cells, but how many of you know about hereditary cancers? As per studies, about 5 to 10 per cent of cancers are thought to be hereditary. A hereditary cancer syndrome (HCS) is a genetic predisposition to certain types of cancer, often with onset at an early age, caused mostly by the inherited pathogenic variants in one or more genes.
To understand more about hereditary cancer and the various ways one can prevent them, we have with us Dr Mansi Munshi, Consultant Radiation Oncologist, Ruby Hall Clinic. Here are some information about hereditary cancers that the doctor wants you to know.
All human beings have "tumor suppressor" genes, which are responsible for repairing random mistakes happening in our DNA every day - thus preventing tumor formation. If these genes are unable to carry out their function because of a defect in its structure then those individuals may be at risk of certain groups of cancer. Most of these genes are inherited in an "autosomal dominant" manner, which means that they may pass on from one generation to the next with a 50% probability and have nothing to do with looks, personality or gender. This means that one cannot guess if a gene has been passed on based on these attributes.
The most famous of these is the BRCA gene which is related to breast and ovarian cancer syndrome (HBOCS). It was widely popularized by the Hollywood actress Angelina Jolie and significant awareness of this exists in the doctor and patient community. However, BRCA (1 and 2) represent only a fraction of the genes which may be responsible for HBOCS. Increased genetic testing in recent years has revealed many other "non-BRCA" genes which could be involved.
Here are a few FAQs related to this topic
Speaking to TheHealthSite.com, Dr Mansi Munshi answered some of the common questions about hereditary cancer.
You may like to read
1) Do all patients of breast or ovarian cancer need to undergo genetic testing?
While current recommendations suggest that all ovarian cancers should undergo genetic testing, we look for red flags in breast cancer patients. These could be an unusually young age, Triple negative type breast cancer, breast cancer in both the breasts and of course, a family history of cancer.
2) How does testing help?
Discovering hereditary cancer could impact treatment decisions such as the type of surgery and targeted chemotherapy. It also helps identify family members and children who share the same gene and are at risk for developing cancer.
3) Can you change a patient's genetic status? How can one prevent cancer?
No, at present genetic editing is not done. However, if a faulty gene is identified then preventive action with appropriate screening can be offered to catch cancer in the earliest stages and improve survival. Organs which can be sacrificed may be removed too at appropriate age if they are at significant risk.
4) Can anyone undergo testing? How is it done?
Genetic testing is recommended only after adequate counselling if found necessary by the specialist, as the results could have a major psychological and social impact on a person's life. The genetic test requires a person's blood or saliva sample.
5) Are breast and ovary the only cancer which can be prevented?
Any family history of cancer should be evaluated as there are several other syndromes which can be hereditary, such as Lynch syndrome related to uterine and colorectal cancers, hereditary thyroid cancers etc.
6) What should one do if one wants to seek advice?
They must ask their oncologist if they are under treatment for cancer or reach out to a cancer genetic specialist.
Genetic testing must be avoided without counselling.